Final answer:
The missing term is 'conductivity,' which describes the ability of an organism to transmit heat through various mechanisms such as radiation, evaporation, convection, and conduction.
Step-by-step explanation:
The term you are looking for to fill in the blank is “conductivity.” The sentence should read: Thermal conductivity is the ability of an organism to transmit heat. In biological contexts, this term describes the mechanisms through which animals exchange heat with their environment. Heat can be exchanged between an animal and its environment through four mechanisms: radiation, evaporation, convection, and conduction. For example, heat is removed from a mammal's body when they sweat and it evaporates, cooling the body down. Additionally, animals can also gain or release heat through direct contact with another surface (conduction), or by air or water moving adjacent to them (convection). The ability to radiate or absorb heat through electromagnetic waves is also a vital mechanism for temperature regulation in animals.